Re: [PATCH v2 4/8] drm/sun4i: vi_layer: Limit formats for DE33

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Exposing YCBCR color properties on a plane that does not support YUV formats introduces UAPI inconsistency.
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commit 929b63037079ff8fc9eaecabce5ad91bde84083f
Author: Jernej Skrabec <jernej.skrabec@gmail.com>

drm/sun4i: vi_layer: Limit formats for DE33

This commit removes YUV formats from the supported list for DE33 planes
without scaler support. A new format array containing only RGB formats is
introduced and used when scaling is unavailable.

> diff --git a/drivers/gpu/drm/sun4i/sun8i_vi_layer.c b/drivers/gpu/drm/sun4i/sun8i_vi_layer.c
> --- a/drivers/gpu/drm/sun4i/sun8i_vi_layer.c
> +++ b/drivers/gpu/drm/sun4i/sun8i_vi_layer.c

[ ... ]

> @@ -410,8 +437,17 @@ struct sun8i_layer *sun8i_vi_layer_init_one(struct drm_device *drm,
>  	layer->cfg = cfg;
>  
>  	if (layer->cfg->de_type >= SUN8I_MIXER_DE3) {
> -		formats = sun8i_vi_layer_de3_formats;
> -		format_count = ARRAY_SIZE(sun8i_vi_layer_de3_formats);
> +		/*
> +		 * TODO: DE33 drivers doesn't support scaling yet, which is a
> +		 * requirement for YUV support.
> +		 */
> +		if (layer->cfg->scaler_mask & BIT(phy_index)) {
> +			formats = sun8i_vi_layer_de3_formats;
> +			format_count = ARRAY_SIZE(sun8i_vi_layer_de3_formats);
> +		} else {
> +			formats = sun8i_vi_layer_de3_no_yuv_formats;
> +			format_count = ARRAY_SIZE(sun8i_vi_layer_de3_no_yuv_formats);
> +		}

Since sun8i_vi_layer_de3_no_yuv_formats only contains RGB formats, should
the driver skip calling drm_plane_create_color_properties() for this
configuration?

Later in sun8i_vi_layer_init_one(), the driver unconditionally calls
drm_plane_create_color_properties(), which exposes YCBCR color encoding and
range UAPI properties. Could this expose confusing or meaningless YUV
properties to userspace for planes where only RGB formats are supported?

>  	} else {
>  		formats = sun8i_vi_layer_formats;
>  		format_count = ARRAY_SIZE(sun8i_vi_layer_formats);

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Sashiko AI review · https://sashiko.dev/#/patchset/20260509190015.79086-1-jernej.skrabec@siol.net?part=4